CleanTechnica Interview with Energy Vault CEO: PSH Energy Storage & Recycling Coal Ash

I was recently invited to interview Energy Vault President, Co-Founder and CEO Robert Piconi, who shared some of Energy Vault’s latest accomplishments and what sets it apart from its competitors in the storage industry. ‘energy. Energy Vault’s mission is to accelerate the decarbonization of our planet by introducing the most advanced, environmentally friendly and economical energy storage technologies. Robert explained how Energy Vault works to achieve this and highlighted these important points:

  • Energy Vault does not use lithium.
  • Energy Vault uses sustainable materials in its products.
  • Saudi Aramco has invested in Energy Vault.

The idea

Robert told me that Entergy Vault was founded four years ago in collaboration with someone from Idealab (Bill Gross). “I’ve known Bill for about 15 years and he called me about this idea he had for energy storage.”

He explained that the idea has evolved from what it initially was. Energy storage is a difficult problem to solve. He spoke about the cost issues associated with storing solar energy while noting that solar energy is now cheaper than ever. Energy Vault does not use lithium-ion batteries to store electricity produced by solar energy. Instead, it uses pumped storage hydropower (PSH).

“The cheapest storage, which was historically hydroelectricity, is between 15 and 20 cents per kilowatt hour. When you look at wind and solar – a hundred or two and you have natural gas, which is five cents. You can see why people haven’t rolled out renewables quickly because the cost of storing them is so high. “

He explained that Bill had called him with the idea of ​​taking pumped hydroelectricity – mostly by gravity – but instead of building big dams and damaging the ecosystem, the idea was to build a structure ( to take advantage of gravity you need height) which would only use composite blocks made with earth. These organic composite blocks are the storage medium.

“We take the excess wind and solar power. It powers the motors, and when there is excess, it stacks these composite blocks up high. This is all the potential energy in height – the weighted height is the potential energy. And then we have a software platform that automates this whole process.

“When the network sends a signal that it needs power, the software kicks in and it’ll pull down those composite blocks. It runs the engine and creates electricity and simply charges it onto the grid.

Robert explained that unlike lithium-ion batteries, PSH does not degrade over time. He added that Energy Vault solved the problem without using concrete, making it extremely low cost.

“For the first time, you can take low-cost wind and solar – one to two cents – and pair them with low-cost, large-scale energy storage. Since we don’t degrade over time, can be built locally, and don’t have scarce materials, this is something that achieves a leveled cost – ultra-low – and therefore can be deployed at large scale. This is how we created Energy Vault.

“What is really important to us, the company, is that we stick to three parameters. For us, number one was the time and urgency to get it to market quickly. That’s why we didn’t focus on chemistry or science roadmaps over time – that would be uncertain. It also meant that we wanted to build something quickly. Meaning, not something that would take years to build or have a supply chain.

“The second parameter that was important was the economy. I mentioned going down at super low cost so it meant some materials were off limits.

“And then the third thing was environmental sustainability. So it’s our own. We use sustainable materials and avoid things like concrete. We also have a local supply chain, which minimizes greenhouse gases from the transportation sector. We’re building it locally, so it’s good for local economies and jobs.

“This is becoming an interesting addition to lithium-ion, which focuses more on shorter durations such as electric vehicles and some shorter-lived energy stores. We become a very interesting and scalable supplement to sort of make the highest duration, 2-4 hours, but bringing it to 6, 8, 10 and 12 hours in a transparent, economical way with very high efficiency.

Composite blocks

The composite blocks that make up the support used are mostly made of earth but can also contain materials such as coal ash, which usually ends up in landfills. Robert explained that the blocks have environmentally sustainable solutions that use waste. Other types of waste include removed wind turbine blades and tailings from the mining industry.

The photo below is a screenshot of Energy Vault Presentation to investors. You can see the composite blocks and the details of how wastes such as unrecycled coal ash can be recycled and used to store solar and wind power.

Screenshot of the Energy Vaults investor presentation

The composite blocks used in the tests consisted of 96% innovated soil with a Cemex polymer developed which would allow soil and water to be mixed with cement powder. This allows Energy Vault to avoid the use of concrete.

1/4 scale model

Robert explained that they built a quarter scale model and tested it. Then they went up to scale. SoftBank backed the company with an investment it used to build a 5MW system, shown in the video above. This is the first generation and Energy Vault and its customers have tested it.

This culminated in the agreements Energy Vault signed with Saudi Aramco – announced last spring. Enel Green Power is another company partnering with Energy Vault to integrate decommissioned wind turbine blades into Energy Vault’s gravitational energy storage technology.

Circular economy

Using waste coal and decommissioned wind turbines in the soil product is an integral part of Entergy Vault’s circular economy. Robert explained the different types of coal ash and noted that coal-fired power plants generate millions of tonnes of coal combustion residue (CCR). The Energy Vault product is a solution to this, helping to convert waste into energy.

Saudi Aramco

Energy Vault pumped storage hydroelectric power

Image courtesy of Energy Vault

One thing Robert wanted to stress is the importance of investments and partnerships with Saudi Aramco and Enel. The former is the world’s largest energy company and the latter is the world’s largest independent power producer (IPP). Bringing them into the Energy Vault circular economy plan is exciting, Robert told me.

Regarding Saudi Aramco, a fossil fuel company, which supports Energy Vault, Robert said:

“I am really excited about their support for our storage. And the fact that they have invested in our company, what does that mean? This means they are behind it strategically for Aramco and their needs to make the clean energy transition. It’s a massive signal of what has been a traditional OPEC leader and a company people clearly expect to help not only transition but lead.

“I think that’s a great signal and the fact that they’re going to switch to alternative fuels like using the sun to produce green hydrogen, for example, is a perfectly clean fuel. So I think that’s a great signal and we’re very happy to have their support, as some of our most important initial deployments are going to be in the Middle East.

Images courtesy of Energy chest

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